The present invention relates to a novel method for removing a wallpaper sheet adhesively attached to a wall body surface of, e.g., a living house, off the wall body surface as well as to a wallpaper remover solution used in the method.
As is known, wallpaper sheets used on the interior walls of living houses and other buildings can be classified into several different types including those consisting of a single paper sheet, those consisting of a paper sheet as a substrate provided with a coating layer of a vinyl resin and those as a laminate consisting of a paper or resin-film substrate and a laminating film of a vinyl resin. These wallpaper sheets are coated on one surface usually with a pressure-sensitive adhesive to form an adhesive lining layer and press-attached onto the surface of a wall body to be bonded thereto with intervention of a layer of the pressure-sensitive adhesive.
It is sometimes necessary when repairing of the wall or redesigning of the room is desired that the wallpaper sheet bonded firmly to the wall body surface with an adhesive is removed by peeling off the surface presenting a substantial amount of job depending on the properties of the substrate sheet and types of the pressure-sensitive adhesive which can be a starch-based, acrylic resin-based or cellulosic resin-based adhesive either singly or as a blend.
Accordingly, it is a usual practice that peeling of the wallpaper sheet off the wall body surface is carried out after soaking the paper sheet with water because most of the above named pressure-sensitive adhesives absorb water and become softened to decrease the adhesive bonding strength. A problem there is that the permeability of fresh water alone as a wallpaper remover through the wallpaper sheet is not high enough to facilitate peeling of the wallpaper sheet within a short time or the fresh water applied to the wallpaper surface is rapidly lost by dripping or by evaporation before exhibiting an effect as a remover liquid.
Several proposals and attempts have been made heretofore as a countermeasure to this problem including a method in which the remover liquid is an aqueous solution prepared by dissolving a gelation agent or thickening agent in water to increase viscosity or consistency of the water so that the solution can be retained in contact with the wallpaper sheet for an extended length of time without dripping and a method in which water is supplied to the wallpaper sheet in the form of water vapor or steam by using a steaming humidifier. However, the former method is not quite effective when the wallpaper sheet is water-resistant and the latter method cannot be undertaken with high working efficiency due to the use of a heavy humidifier instrument if not to mention an eventual danger of scalding of workers.
As a further countermeasure to the problem, especially, when the wallpaper sheet is water-resistant, several methods are proposed in U.S. Pat. Nos. 4,067,773, 4,092,175 and 4,274,884, U.K. Patent Application No. 2,058,122A, German Patent 1,806,026 and Japanese Patent Kokai No. 6-250729, according to which the surface of a wallpaper sheet is rubbed with a wire brush or scratched with a knife edge to destroy the water-impermeable surface layer of the sheet followed by soaking of the sheet with an aqueous remover solution prepared by dissolving a surface active agent, an enzyme, a gelation agent, a thickening agent, a water-miscible organic solvent or other additives in water. Although these methods are not ineffective for the purpose of facilitating removal of a wallpaper sheet from a wall body surface by peeling, the effectiveness is quite insufficient in some cases depending on the types of the wallpaper sheets and the nature of the pressure-sensitive adhesives so that it is eagerly desired to develop a novel and more effective water-base remover solution for wallpaper sheets or a more efficient method of removing a wallpaper sheet from a wall body surface.